The role played by viruses in the production of disease was readily recognized in the past due to their ability to cause cell death in vivo and in vitro with concomitant physiologic and cytologic effects. These factors play a prominent role in the pathogenesis of many viral diseases. It has been shown, however, that viruses may alter cells in other ways, without leading to cell death, adding a new dimension to the studies of viral pathogenesis. In view of this, a study of noncytolytic virus infections, particularly virus-induced malignant transformation, is proposed to investigate the results of infections by these viruses on the salivary glands. These tissues are particularly important in the ecology of the oropharynx since a relationship is known to exist between the functional status of the glands and the environment of the oral cavity. By the use of isotopically labelled precursors, the metabolism will be studied and related to gland functions such as metabolite uptake, production of salivary enzymes, lipids and glycoproteins, and the results of virus infection and malignant transformation on these processes. Cell metabolism will be examined by the use of labelled precursors. Isoenzymes will be examined by electrophoresis and electrofocusing. Lipid metabolism will be examined by chromatography and autoradiography. Enzyme production and release qualitatively and quantitatively will be studied by use of a perifusion chamber. The use of noncytolytic viruses, such as polyoma virus, is well suited to these studies since the infected cells may retain normal type functions as well as acquiring new or altered properties.